Family of exactly solvable models with an ultimative quantum paramagnetic ground state

TL;DR

This paper introduces a family of exactly solvable 2D frustrated quantum magnet models with highly degenerate ground states called ultimate quantum paramagnets, which have potential applications in quantum computation.

Contribution

It presents a new class of solvable frustrated quantum magnet models based on quantum cages with chiral degrees of freedom, expanding understanding of quantum spin liquids.

Findings

Ground states are extensively degenerate with zero-temperature entropy.

Models exhibit unusual excitations with high degeneracy.

Implications for thermodynamics and decoherence-free quantum computation are discussed.

Abstract

We present a family of two-dimensional frustrated quantum magnets solely based on pure nearest-neighbor Heisenberg interactions which can be solved quasi-exactly. All lattices are constructed in terms of frustrated quantum cages containing a chiral degree of freedom protected by frustration. The ground states of these models are dubbed ultimate quantum paramagnets and exhibit an extensive entropy at zero temperature. We discuss the unusual and extensively degenerate excitations in such phases. Implications for thermodynamic properties as well as for decoherence free quantum computation are discussed.